Intervertebral implants and related systems and methods

ABSTRACT

Disclosed are intervertebral devices for insertion between and/or adjacent to vertebrae of a patient, incorporating apertures for fastening devices which include fastener locking and/or retaining elements.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/956,084, filed Jan. 1, 2015 and entitled “INTERVERTEBRAL IMPLANTS ANDRELATED SYSTEMS AND METHODS,” the disclosure of which is incorporatedherein by reference in its entirety.

TECHNICAL FIELD

Various aspects of the present disclosure relate generally tointervertebral implants and related systems and methods. Morespecifically, the present disclosure relates to intervertebral devices,systems, and methods for deployment within a body of a patient.

BACKGROUND OF THE DISCLOSURE

As shown in FIG. 1, a patient's spinal column 2 includes twenty-sixbones called vertebrae 4 which protect the spinal cord. While the shapeand/or size of each vertebra 4 varies depending on the placement,loading, posture, and/or pathology within spinal column 2, each vertebra4 is composed of cancellous bone, which is a spongy type of osseoustissue. The cancellous bone of each vertebra 4 is then covered by a thincoating of cortical bone, which is a hard and dense type of osseoustissue. An intervertebral disc 6 is positioned between each pair ofadjacent vertebrae 4 in spinal column 2. Each disc 6 forms afibrocartilaginous joint between adjacent vertebrae 4 so as to allowrelative movement between adjacent vertebrae 4. Beyond enabling relativemotion between adjacent vertebrae 4, each disc 6 acts as a shockabsorber for spinal column 2.

Each disc 6 comprises a fibrous exterior surrounding an inner gel-likecenter which cooperate to distribute pressure evenly across each disc 6,thereby preventing the development of stress concentrations that mightotherwise damage and/or impair vertebrae 4 of spinal column 2. Discs 6are, however, subject to various injuries and/or disorders which mayinterfere with a disc's ability to adequately distribute pressure andprotect vertebrae 4. For example, disc herniation, degeneration, andinfection of discs 6 may result in insufficient disc thickness and/orsupport to absorb and/or distribute forces imparted to spinal column 2.Disc degeneration, for example, may result when the inner gel-likecenter begins to dehydrate, which may result in a degenerated disc 8having decreased thickness. This decreased thickness may limit theability of degenerated disc 8 to absorb shock which, if left untreated,may result in pain and/or vertebral injury.

While pain medication, physical therapy, and other non-operativeconditions may alleviate some symptoms, such interventions may not besufficient for every patient. Accordingly, various procedures have beendeveloped to surgically improve patient quality of life via abatement ofpain and/or discomfort. Such procedures may include, discectomy andfusion procedures, such as, for example, anterior cervical interbodyfusion (ACIF), anterior lumbar interbody fusion (ALIF), direct lateralinterbody fusion (DLIF) (also known as XLIF), posterior lumbar interbodyfusion (PLIF), and transforaminal lumbar interbody fusion (TLIF). Duringa discectomy, all or a portion of a damaged disc, e.g., a degenerateddisc 8, is removed via an incision, typically under X-ray guidance.

Following the discectomy procedure, a medical professional may determinean appropriate size of interbody device 10 (FIG. 2) via one or moredistractors and/or trials of various sizes. Each trial and/or distractormay be forcibly inserted between adjacent vertebrae 4. Upondetermination of an appropriate size, one or more of an ACIF, ALIF,DLIF, PLIF, and/or TLIF may be performed by placing an appropriateinterbody device 10 (e.g., a cage, spacer, block) between adjacentvertebrae 4 in the space formed by the removed degenerated disc 8.Placement of such interbody devices 10 within spinal column 2 mayprevent spaces between adjacent vertebrae 4 from collapsing, therebypreventing adjacent vertebrae 4 from resting immediately on top of oneanother and inducing fracture of vertebra 4, impingement of the spinalcord, and/or pain. Additionally, such interbody devices 10 mayfacilitate fusion (e.g., bone to grow together) between adjacentvertebrae 4 by stabilizing adjacent vertebrae 4 relative to one another.Accordingly, as shown in FIG. 2, such interbody devices 10 often mayinclude one or more fixation members such as, for example, screws 12extending through interbody device 10 and into adjacent vertebrae 4.

Often, following the removal of the distractor and/or trial, a medicalprofessional must prepare one or more bores or holes in a vertebra 4intended to receive screws 12. Such holes may be formed with the aid ofa separate drill guide positioned proximate or abutting vertebra 4 andinserting a drill therethrough. Alternatively, such holes may be formedfree hand, without the use of a drill guide. Further, since spinalcolumn 2 is subject to dynamic forces, often changing with each slightmovement of the patient, such screw(s) 12 have a tendency to back out(e.g., unscrew) and/or dislodge from interbody device 10, therebylimiting interbody device's 10 ability to stabilize adjacent vertebrae4, and consequently, promote fusion. Additionally, if screw(s) 12 backout and/or dislodge from interbody device 10, they may inadvertentlycontact, damage, and/or irritate surrounding tissue. Further, interbodydevice 10 is commonly comprised of a radiopaque material so as to bevisible in situ via x-ray and other similar imaging modalities. However,such materials may impede sagittal and/or coronal visibility, therebypreventing visual confirmation of placement and post-operative fusion.

Thus, there remains a need for improved interbody devices, associatedsystems, and methods relating thereto.

SUMMARY

Examples of the present disclosure relate to, among other things,intervertebral implants. Each of the embodiments disclosed herein mayinclude one or more of the features described in connection with any ofthe other disclosed embodiments.

In one example, an intervertebral device may include a body configuredfor insertion between adjacent vertebrae of a patient. The body mayinclude a wall having a first surface, a second surface, and a thicknessextending between the first and second surfaces. The wall may include athrough aperture extending between a first opening on the first surfaceand a second opening on the second surface. The through apertureconfigured to receive a fastening element. A recess may be disposed in aside wall of the aperture and may extend into the thickness of the bodyin a direction substantially transverse to an axis of the aperture.Additionally, at least one offsetting element may be positioned adjacentthe through aperture. The at least one offsetting element may beconfigured to apply a force to the fastening element.

Additionally or alternatively, examples of the device may include one ormore of the following features: application of a force on the fasteningelement by the at least one offsetting element may be configured tolaterally urge the fastening element relative to the recess; upon theapplication of a force on the fastening element by the at least oneoffsetting element, interference between the at least one offsettingelement, the recess, and the fastening element may be configured to urgethe fastening element in a posterior direction relative to the recess;the recess may be configured to retain the fastening element within thethrough aperture; the recess may be configured to receive an actuationportion of the fastening element; the fastening element may be a screw,and the recess may be configured to receive a head of the screw;actuating the at least one offsetting element may cause the at least oneoffsetting element to engage a portion of the fastening element; the atleast one offsetting element may be eccentrically shaped; the at leastone offsetting element may include at least one of a planar portion anda concave portion, and wherein the at least one offsetting elementsincludes a convex portion; the at least one offsetting element may bemovable relative to the body; the fastening element may be a firstfastening element, the device may further include a second fasteningelement, the through aperture may be configured to receive each of thefirst fastening element and the second fastening element; application ofa force on the second fastening element by the at least one offsettingelement may be configured to laterally urge the second fastening elementrelative to the recess; the at least one offsetting element may bepositioned between each of the first fastening element and the secondfastening element, and actuation of the at least one offsetting elementmay be configured to laterally urge the first fastening element and thesecond fastening element relative to the recess, simultaneously; and theat least one offsetting element may be a first offsetting element, thedevice may further include a second offsetting element positionedadjacent said through aperture, application of a force on the secondfastening element by the second offsetting element may be configured tolaterally urge the second fastening element relative to the recessindependently of the first fastening element.

In another example, an intervertebral device may include a bodyconfigured for insertion between adjacent vertebrae of a patient. Thebody may include a wall having a first surface, a second surface, and athickness extending between the first and second surfaces. The wall mayinclude a through aperture extending between a first opening on thefirst surface and a second opening on the second surface. The body mayalso include two lateral supports extending from the first wall. Eachlateral support may define a first window and a second window along alateral surface of the body. The device may further include a fasteningelement positioned within the through aperture and at least oneoffsetting element positioned adjacent said through aperture.

Additionally or alternatively, examples of the device may include one ormore of the following features: at least a portion of the body may beradiopaque and each of the first and second windows may be radiolucent;a radiolucent graft containment sheath may be disposed about the body;and the body may include a tapered keel.

In another example, an intervertebral device may include a bodyconfigured for insertion between adjacent vertebrae of a patient. Thebody may include a wall having a first surface, a second surface, and athickness extending between the first and second surfaces. The wall mayinclude a through aperture extending between a first opening on thefirst surface and a second opening on the second surface. The body alsomay include two lateral supports extending from the wall. Each lateralsupport may define a first window and a second window along a lateralsurface of the body. The body may further define at least one windowalong the wall of the body. Additionally, the device may include aradiolucent graft containment sheath disposed about the body.

Additionally or alternatively, examples of the device may include one ormore of the following features: the body may be radiopaque and each ofthe first and second windows may be radiolucent; the body may include atapered keel; the tapered keel may be offset from an anterior-mostsurface of the body; a graft retention member may extend along at leasta portion of the body; and a plurality of protrusions may extend alongthe body.

It may be understood that both the foregoing general description and thefollowing detailed description are exemplary and explanatory only andare not restrictive of the invention, as claimed.

As used herein, the terms “comprises,” “comprising,” or other variationsthereof, are intended to cover a non-exclusive inclusion such that aprocess, method, article, or apparatus that comprises a list of elementsdoes not include only those elements, but may include other elements notexpressly listed or inherent to such a process, method, article, orapparatus. Additionally, the term “exemplary” as used herein is used inthe sense of “example,” rather than “ideal.”

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate exemplary arrangements of thepresent disclosure and together with the description, serve to explainthe principles of the disclosure.

FIG. 1 illustrates a patient's spinal column;

FIG. 2 illustrates an interbody device positioned within the patient'sspinal

FIG. 3A illustrates an exemplary screw blocking mechanism prior toinsertion of a screw;

FIG. 3B illustrates the screw blocking mechanism of FIG. 3A, afterinsertion of a screw, in an unlocked configuration;

FIG. 3C illustrates the screw blocking mechanism of FIG. 3B in a lockedconfiguration;

FIG. 4 illustrates a further exemplary screw blocking mechanism;

FIGS. 5A and 5B illustrate a still further exemplary screw blockingmechanism;

FIG. 5C illustrates a partial cross-sectional view of the exemplaryscrew blocking mechanism of FIGS. 5A and 5B;

FIGS. 5D and 5E illustrate partial cross-sectional views of theexemplary screw blocking mechanism of FIGS. 5A and 5B underinterference;

FIGS. 6A and 6B illustrate another exemplary screw blocking mechanism;

FIG. 7 illustrates an exemplary aperture of a screw blocking mechanism;

FIGS. 8A and 8B illustrate a further exemplary screw blocking mechanism;

FIGS. 9-12 illustrate exemplary screw blocking mechanisms according tofurther arrangements;

FIGS. 13A and 13B illustrate a still further exemplary screw blockingmechanism;

FIGS. 14A and 14B illustrate another exemplary screw blocking mechanism;

FIGS. 15 and 16 illustrate exemplary screw blocking mechanisms accordingto further arrangements;

FIG. 17 illustrates yet another exemplary screw blocking mechanism;

FIGS. 18-21 illustrate exemplary screw blocking mechanisms according tofurther arrangements for use with multiple screws in a single bore;

FIGS. 22A-22D illustrate another exemplary screw blocking mechanism;

FIGS. 23-27 illustrate exemplary standalone interbody devices;

FIGS. 28-32 illustrate exemplary composite interbody devices;

FIGS. 33 and 34 illustrate a perspective and side view of an exemplaryinterbody device, respectively;

FIGS. 35 and 36 illustrate a perspective and side view of anotherexemplary interbody device, respectively;

FIGS. 37 and 38 illustrate a perspective and side view of a stillfurther exemplary interbody device, respectively;

FIGS. 39-41 illustrate a perspective and side views of another exemplaryinterbody device, respectively;

FIG. 42 illustrates an interbody device including packed bone graftmaterial;

FIG. 43 illustrates an interbody device including at least one retentionmember;

FIGS. 44-49 illustrate exemplary retention member arrangements;

FIGS. 50 and 51 illustrate exemplary protrusion features of an interbodydevice;

FIGS. 52-54 illustrate exemplary keel features of an interbody device;

FIGS. 55 and 56 illustrate an exemplary interbody device;

FIGS. 57-60 illustrate various views of a further exemplary interbodydevice;

FIGS. 61-63 illustrate various views of yet another exemplary interbodydevice;

FIGS. 64-67 illustrate various view of a further exemplary interbodydevice;

FIG. 68 illustrates another exemplary interbody device;

FIG. 69A illustrates a stacked exemplary interbody device;

FIGS. 69B-D illustrate perspective views of exemplary interbody devicesof the stacked interbody device of FIG. 69A;

FIGS. 70-75 illustrate exemplary arrangements of a face of an interbodydevice;

FIGS. 76 and 77 illustrate exemplary aperture arrangements of aninterbody device;

FIGS. 78A-78E illustrate exemplary multi-vertebrae devices;

FIG. 79 illustrates an exemplary distractor and/or trial tool;

FIGS. 80A and 80B illustrate the exemplary tool of FIG. 79 in use;

FIG. 81 illustrates an exemplary composite tool and cage of an interbodydevice;

FIGS. 82A-82C illustrate the composite tool and cage of FIG. 81 in use;

FIGS. 83-87 illustrate exemplary interbody devices positioned betweenadjacent vertebra; and

FIGS. 88-91 illustrate exemplary multi-vertebrae devices.

DETAILED DESCRIPTION

Screw Blocking Mechanisms

FIGS. 3A-3C illustrate an exemplary system for preventing fixationdevices such as screws 12 from backing out (e.g., unscrewing) and/ordislodging from interbody device 10. As used herein, such systems may beconsidered screw blocking mechanisms. As shown in FIG. 3A, an exemplaryinterbody device 10 may include a wall having a first face 14, anopposite second face, and a thickness extending therebetween. Face 14may define a screw receiving face in a substrate (e.g., a plate and/orblock) of interbody device 10. For example, the substrate of interbodydevice 10 may be comprised of any one or more of metal, metal alloys,plastics, ceramics, and elastomers capable of receiving and retainingscrew 12 therein. Face 14 may define an aperture 16 configured toreceive, engage, and/or complement a head 18 (e.g., an actuationportion) of screw 12 therein. While only a single aperture 16 isdepicted in FIG. 3A, face 14 may define any appropriate number ofapertures 16. For example, in some arrangements, face 14 may define two,three, four, or more apertures, as will be described in further detailbelow. Aperture 16 may have any appropriate shape configured to receiveone or more screws 12 therein. For example, as shown in FIG. 3A,aperture 16 may be generally circular. In other arrangements describedbelow, however, aperture 16 may be generally ovular, triangular, square,cross-shaped, and or irregular. Additionally, aperture 16 may be taperedso as to receive screw 12 at an angle therethrough. Aperture 16 may be athrough hole and/or a counterbore. For example, aperture 16 may extendfrom a first opening on face 14 through the thickness of the wall ofinterbody device 10 to the second face, opposite face 14.

A sidewall of aperture 16 may a define a recess 20 extending into thedirection the thickness in a direction substantially transverse to anaxis of aperture 16 and having a surface 22 configured to cooperate withand/or correspond in profile with head 18 of screw 12. For example,surface 22 may be generally curved, arcuate, and/or rounded so as toreceive, engage, complement, and/or mate with an exterior side and/ortop surface of generally curved, arcuate, and/or rounded head 18 ofscrew 12. As shown in FIG. 3A, recess 20 may comprise a pocket or spaceinto which head 18 may be moved upon the application of a substantiallylateral force, as will be described in further detail below. As shown inFIG. 3A, aperture 16 may define a single (e.g., only one) recess 20. Inother arrangements, however, aperture 16 may define multiple recesses 20corresponding in number to a number of screws 12 to be received withinaperture 16, as will be described in further detail below.Alternatively, aperture 16 may define a different number of recesses 20than a number of screws 12 to be received within aperture 16, as will bedescribed in further detail below.

The substrate of interbody device 10 may further include an offsettingelement 24. As shown in FIG. 3A, offsetting element 24 may be positionedadjacent aperture 16 so as to cooperate with head 18 to prevent screw 12from backing out (e.g., unscrewing) or dislodging from interbody device10. Further, offsetting element 24 may be movably received within thesubstrate of interbody device 10. For example, in some arrangements,offsetting element 24 may be rotatably received within the substrate ofinterbody device 10. In other arrangements, however, offsetting element24 may be configured for lateral or translational movement with respectto the substrate of interbody device 10. For example, offsetting element24 may include a wedge element configured to be inserted between screwhead 18 and aperture 16 so as to laterally urge or otherwise bias screwhead 18 toward and/or into recess 20. Alternatively, offsetting element24 may include a spring element configured to bias screw head 18laterally toward recess 20. Further, in some arrangements, offsettingelement 24 may include a sliding element configured to laterally urgescrew head 18 toward recess 20. Still further, offsetting element 24 mayinclude one or more shape memory alloy (SMA) portions comprising a SMAmaterial, such as, for example, NITINOL™. Such materials, uponactivation (e.g., application of heat and/or exposure to bodychemistry), reform to a “remembered” shape. That is, upon application ofan activating force, offsetting element 24 may transition to its“remembered” configuration and laterally urge screw head 18 towardsrecess 20. In yet a further example, any of the above noted offsettingelements 24 may be used in combination with one another so as to producea composite actuation force.

As shown in FIG. 3A, offsetting element 24 may include a cam head 26coupled to a shaft 28. Shaft 28 may extend into the substrate ofinterbody device 10 and include any appropriate threading or similarretention mechanism (FIG. 5C) configured to movably couple offsettingelement 24 to interbody device 10. Accordingly, interbody device 10 mayinclude an internally threaded bore for cooperation with shaft 28. Camhead 26 may include an actuator receiving element such as, for example,a hex-shaped bore 30 configured to cooperate with any appropriaterotatable driver (e.g., key, screw driver, hex driver, etc.). While bore30 is described and illustrated as a hex-shaped bore 30, it isunderstood that any appropriately shaped bore may be used so as tocooperate with any correspondingly shaped driver and/or driver tip. Camhead 26 may be eccentrically and/or irregularly shaped. For example, asshown, cam head 26 may include a crescent-shaped member have a convexportion 32 and a concave portion 34. Concave portion 34 may bediametrically spaced from convex portion 32. More particularly, concaveportion 34 may include a radius of curvature similar to the radius ofcurvature of aperture 16. Cam head 26 may further include one or moretactile, visual, or other indicia 25 configured to facilitate a medicalprofessional in determining whether offsetting element 24 is in theunlocked configuration (FIGS. 3A, 3B) or the locked or blockedconfiguration (FIG. 3C). In one exemplary arrangement, indicia 25 mayinclude an arrow pointed or directed toward concave portion 34.Alternatively, concave portion 34 may be replaced with a substantiallyflat planar surface, or a convex configuration (not shown).

In an unlocked configuration, prior to insertion of screw 12 intointerbody device 10, as shown in FIG. 3A, concave portion 34 may bepositioned adjacent to aperture 16 while convex portion 32 is positionedaway or spaced from aperture 16. Thus, as a result of concave portion 34including a similar curvature as aperture 16, offsetting element 24 doesnot extend into aperture 16. That is, in the unlocked configuration,concave portion 34 may form a side-wall of aperture 16. In other words,concave portion 34 may complete, or otherwise continue (e.g., fills in)the circular shape of aperture 16. Upon movement or rotation of cam head26 to a locked or blocked configuration (FIG. 3C), convex portion 32 ispositioned adjacent aperture 16 while concave portion 34 is positionedaway or spaced from aperture 16. Consequently, convex portion 32 extendsinto or otherwise protrudes into aperture 16.

FIGS. 3B and 3C illustrate an exemplary manner of preventing screw 12from backing out (e.g., unscrewing) and/or dislodging from interbodydevice 10. For example, FIG. 3B illustrates interbody device 10 havingoffsetting element 24 in the unlocked configuration in which screw 12has been positioned within aperture 16. As shown in FIG. 3B, aperture 16may be configured to receive head 18 of screw 12 with sufficientclearance such that screw 12 may be loosely or exactly inserted intoaperture 16. That is, a dimension, diameter, and/or shape of aperture 16may be defined so as to correspond within a desired tolerance to adimension, diameter, and/or shape of head 18 of screw 12. Moreover, head18 may be completely received within aperture 16 so that head 18 isflush and/or below face 14. In the unlocked configuration, as shown inFIG. 3B, a central longitudinal axis 36 of shaft 28 may be positioned ata distance X1 from a central longitudinal axis 38 of screw 12.Accordingly, with distance X1 between shaft 28 of offsetting element 24and screw 12, head 18 of screw 12 may be spaced from surface 22 ofrecess 20.

Upon rotation of offsetting element 24, for example, in direction A asshown in FIG. 3C, cam head 26 of offsetting element 24 may be rotatedsuch that convex portion 32 may be brought in contact with the sidesurface of head 18 of screw 12. As such, screw 12 may be pushed, moved,biased, or otherwise urged laterally toward and/or into recess 20 andthe external side and/or top surface of head 18 of screw 12 may be heldclose to or in contact with surface 22. Additionally, due to the shapeand/or configuration (e.g., curvature) of surface 22 and/or the externalside and/or top surface of head 18, actuation of offsetting element 24may cause interference between head 18 and recess 20 such that head 18is forced downward (e.g., in a posterior (e.g., deeper) direction ofvertebra 4). Accordingly, in the locked or blocked configuration, asshown in FIG. 3C, offsetting element 24 may be configured to retainscrew 12 in interbody device 10. Often, the vertebra 4 into which screw12 is screwed, as described in further detail below, has a relativelylow density such that the laterally directed force applied to screw 12via offsetting element 24 is greater than the resistive force applied byvertebra 4 to screw 12. In some instances, however, the vertebra 4 intowhich screw 12 is screwed has a relatively high density such that theresistive force applied by vertebra 4 to screw 12 is greater than thelaterally directed force applied to screw 12 via offsetting element 24.In such cases, upon actuation of offsetting element 24, screw 12 mayremain stationary while the substrate of interbody device 10 may movelaterally in microscopic motion until the external side and/or topsurface of head 18 may be urged into recess 20. In such a case,actuation of screw offsetting element 24 may place head 18 of screw 12in tension. Accordingly, upon any force being applied to screw 12 whichwould otherwise cause screw 12 to back out (e.g., unscrew) and/ordislodge from vertebra 4 and/or interbody device 10, screw 12 will beurged toward recess 20 and prevented from backing out by a top surfaceof recess 20.

As noted above, face 14 of the substrate of interbody device 10 maydefine a plurality of apertures 16. For example, as shown in FIG. 4,face 14 may define two apertures 16. Each aperture 16 may be configuredto receive one or more screws 12 therein. For example, each aperture 16may be configured to receive a single screw 12. Additionally, similar tothe arrangement described above, each aperture 16 may define a recess 20having a surface 22 configured to cooperate with and/or correspond inprofile to head 18 of screw 12. As shown in FIG. 4, each recess 20 maycomprise a pocket or space into which head 18 may be moved upon theapplication of a lateral force. Each recess 20 may include substantiallysimilar or differing geometric configurations and/or dimensions.Further, as shown in FIG. 4, the substrate of interbody device 10 mayfurther include one or more offsetting elements 24 associated with eachaperture 16. Offsetting elements 24 may be similar in construction andmanner of use as described above in connection FIGS. 3A-3C. In theexample of FIG. 4, each aperture 16 may include a single recess 20,configured to receive a head 18 of a single screw 12 upon actuation ofan individual offsetting element 24. As such, a first screw 12positioned within a first aperture 16 may be moved towards the locked orblocked configuration (FIG. 3C) upon the actuation of a first offsettingelement 24 independently of a second screw 12 positioned within a secondaperture 16. In addition, as shown in FIG. 3C, when offsetting element24 is actuated, only a lateral portion of head 18 at be disposed inrecess 20.

Alternatively, as shown in FIGS. 5A and 5B, multiple screws 12 may bemoved towards a locked or blocked configuration simultaneously. That is,the substrate of interbody device 10 depicted in FIGS. 5A and 5B may besimilar to that of FIG. 4, except that instead of separate offsettingelements 24, a single offsetting element 24 may be positioned betweeneach aperture 16. Accordingly, in such an arrangement, offsettingelement 24 may have a pair of convex portions 32 and a pair of concaveportions 34 disposed therebetween, as shown. The pair of concaveportions 34 may be diametrically spaced from one another. In an unlockedconfiguration, prior to insertion of each screw 12 into interbody device10, as shown in FIG. 5A, a first concave portion 34 may be positionedadjacent to a first aperture 16 while a second concave portion 34 may bepositioned adjacent to a second aperture 16. Further, each of the twoconvex portions 32 may be positioned away or spaced from the first andsecond apertures 16. Upon movement or rotation of cam head 26 of theoffsetting element 24 to the locked or blocked configuration, as shownin FIG. 5B, convex portions 32 are positioned adjacent and protrudinginto apertures 16 while concave portions 34 are positioned away orspaced from apertures 16. In such a manner, a single offsetting element24 may be used to retain two separate screws 12 positioned in twoseparate apertures 16, simultaneously.

It is to be understood that, while the central longitudinal axis 38 ofeach screw 12 of FIGS. 3B and 3C is depicted as extending generallynormal (e.g., perpendicular) to face 14, screws 12 may instead extend ata non-normal (e.g., nonperpendicular) angle relative to face 14.Additionally, while face 14 of the substrate of interbody device 10 isdepicted as substantially planar and/or flat in FIGS. 3A-3C, 4, 5A, and5B, such depictions are merely exemplary. For example, as shown in thecross-sectional view of FIG. 5C, each screw 12 may be positioned at anon-normal angle relative to face 14. Additionally, as shown, face 14may be rounded, curved, and/or otherwise non-planar.

Further, as shown in FIG. 5C, upon rotation of offsetting element 24,convex portions 32 of cam head 26 may be brought in contact with theside surfaces of heads 18 of screws 12. As such, each screw 12 may bepushed, moved, or otherwise urged laterally (in opposing directions)toward recess 20 and the external side and/or top surface of head 18 ofscrew 12 may be received within recess 20. Additionally, due to theshape and/or configuration (e.g., curvature) of recess 20 and/or theexternal side and/or top surface of head 18, actuation of offsettingelement 24 may cause interference between head 18, offsetting element24, and recess 20 such that head 18 is forced downward (e.g., in adeeper or posterior direction of vertebra 4). For example, upon rotation(or other such actuation) of offsetting element 24, head 18 of screws 12may be simultaneously urged laterally toward recess 20 and downward ordeeper into vertebra 4 (e.g., in a posterior direction), as shown inFIGS. 5D and 5E. That is, as shown in FIG. 5D, upon rotation or othersuch actuation of offsetting element 24, convex portions 32 of cam head26 may be brought in contact with the side surfaces of head(s) 18 ofscrew(s) 12 which imparts interference between head 18 and offsettingelement 24 to push, move, or otherwise laterally urge head 18 towardrecess 20. Lateral interference between head 18 and offsetting element24 may be about 0.1 mm. Further, as shown in FIG. 5E, due to theconfiguration (e.g., shape and/or size) of offsetting element 24,lateral force applied to head 18 may impart a simultaneous downward(e.g., in a deeper or more posterior direction of vertebra 4) movementof head 18 relative to offsetting element 24. In some arrangements, head18 may be urged about 0.5 mm downward. Accordingly, in the locked orblocked configuration, as shown in FIG. 5C, offsetting element 24 may beconfigured to retain screw 12 in interbody device 10.

As noted above, each aperture 16 may be configured to receive one ormore screws 12 therein. For example, as shown in FIGS. 6A and 6B, asingle aperture 16 may be configured (e.g., sized) to receive two screws12. That is, aperture 16 may be elongated so as to receive two screws12. While aperture 16 depicted in FIGS. 6A and 6B comprises a generallyovular shape with a single inwardly protruding portion 44 extendingradially inwardly from one side thereof, any other appropriate shapeconfigured to receive two screws 12 therein may be used, as will bedescribed in further detail below.

Additionally, while the arrangement of FIGS. 6A and 6B depict a singleaperture 16, aperture 16 may define two individual and separate recesses20. For example, a first recess 20A may be positioned along a firstportion of aperture 16 while a second recess 20B may be positioned alonga second portion of aperture 16. Each recess 20 may be configured toreceive a single screw 12 of the two screws 12. Additionally, similarlyto the arrangement of FIG. 4, the substrate of interbody device 10 mayfurther include an offsetting element 24 associated with each screw 12.Each offsetting element 24 may be similar in construction and manner ofuse as described above in connection FIGS. 3A-3C. Due to the inclusionof a separate offsetting element 24 associated with each screw 12, eachscrew 12 may be moved towards the locked or blocked configuration, asshown in FIG. 6B, independently of one another.

FIGS. 7, 8A, 8B, and 9-12 illustrate various modifications andarrangements of illustrative examples in accordance with thisdisclosure. For example, as shown in FIG. 7, aperture 16 may begenerally ovular having a substantially constant width w1 so as toreceive two or more screws 12 therein. As shown, the ovular shape ofaperture 16 does not include or is free from any inwardly protrudingportion 44.

Alternatively, as shown in FIG. 8A, aperture 16 may have a variablewidth. That is, aperture 16 may include two lateral portions 42 having afirst width w1 and a central portion 40 have a second width w2. Width w2may be relatively smaller than width w1. That is, central portion 40 maybe a generally narrowed portion of aperture 16. Indeed, central portion40 may define a pair of inwardly protruding surfaces 44. In such anarrangement, head 18 of each screw 12 may be spaced from one another.Indeed, as shown in FIG. 8A, central longitudinal axes 38 of each screw12 may be spaced from one another at a distance of D1. Distance D1 maybe such that a gap G is provided between adjacent side surfaces ofscrews 12.

Further, one or both of the pair of inwardly protruding surfaces 44 maybe configured to cooperate with an offsetting element 24. That is,similarly to the arrangements described above, offsetting element 24 mayinclude at least one convex portion 32 and a pair of concave portions34. In an unlocked configuration, as shown in FIG. 8B, prior toinsertion of each screw 12 into aperture 16, a first concave portion 34may be positioned adjacent to a first lateral portion 42 of aperture 16while a second concave portion 34 may be positioned adjacent to a secondlateral portion 42 of aperture 16. Upon movement or rotation of cam head26 of the offsetting element 24 to the locked or blocked configuration,as shown in FIG. 8A, convex portion 32 may be positioned adjacent one ofthe inwardly protruding portions 44 of aperture 16 while concaveportions 34 are positioned away or spaced from inwardly protrudingportions 44. Thus, as shown in FIG. 8A, convex portion 32 protrudes intofirst and second lateral portions 42. In such a manner, a singleoffsetting element 24 may be used to simultaneously move two separatescrews 12 positioned in a single aperture 16. Alternatively, as shown inFIG. 9, a pair of offsetting elements 24 may be positioned, each so asto cooperate with one of the pair of lateral portions 42. In such amanner, each screw 12 may be moved toward the locked or blockedconfiguration independently of one another.

In some arrangements, as shown in FIG. 10, aperture 16 may define abulbous shape. Similar to aperture 16 described in connection with FIGS.8A, 8B, and 9, aperture 16 of FIG. 10 may have a variable width. Thatis, aperture 16 may include two lateral portions 42 having a first widthw1 and a central portion 40 have a second width w2. Width w2 may berelatively smaller than width w1. That is, central portion 40 may be agenerally narrowed portion of aperture 16, while the two lateralportions 42 may be configured to receive a respective screw 12 therein.As shown in FIG. 10, a separate offsetting element 24 may be positionedadjacent each lateral portion 42. In such a manner, each screw 12 may bemoved toward the locked or blocked configuration independently of oneanother. Alternatively, a single offsetting element 24 may be positionedadjacent one of the pair of inwardly protruding surfaces 44. In such amanner, each screw 12 may be moved toward the locked or blockedconfiguration simultaneously by a single offsetting element 24

As described above, and as shown in FIG. 11, similar to FIGS. 6A and 6B,a single aperture 16 may be configured (e.g., sized) to receive twoscrews 12. Additionally, aperture 16 may define two individual andseparate recesses 20. However, in some arrangements, as shown in FIG.12, aperture 16 may define a single recess 20. In such an arrangement,each screw 12 within aperture 16 may be received within a portion of thesame recess 20. That is, recess 20 may be elongated, extended, orotherwise sized so as to receive both screws 12 therein.

As shown in FIG. 12, for example, one or more offsetting elements 24 maybe associated with each screw 12. Each offsetting element 24 may besimilar in construction and manner of use as described above inconnection with FIGS. 3A-3C. Due to the inclusion of a separateoffsetting element 24 associated with each screw 12, each screw 12 maybe moved towards the locked or blocked configuration, as shown in FIG.12, independently of one another even though both screws 12 may bereceived in a common recess 20. Alternatively, each screw 12 may bemoved towards the locked or blocked configuration simultaneously. Thatis, rather than two offsetting elements 24, a single offsetting element24 may be associated with aperture 16. Additionally, as shown in FIG.12, head 18 of each screw 12 may be positioned within aperture 16 suchthat a side surface of each screw head 18 abuts one another. That is, asshown in FIG. 12, central longitudinal axes 38 of each screw 12 may bespaced from one another at a distance of D2. Distance D2 may be suchthat a very small or no gap G is provided between adjacent side surfacesof screws 12.

As noted above, each aperture 16 may be configured to receive one ormore screws 12 therein. For example, as shown in FIGS. 13A and 13B, asingle aperture 16 may be configured (e.g., sized) to receive threescrews 12. That is, aperture 16 may be shaped so as to receive threescrews 12. While aperture 16 depicted in FIGS. 13A and 13B includes agenerally triangular shape having rounded apices, any other appropriateshape configured to receive three screws 12 therein may be used, as willbe described in further detail below.

Additionally, while the arrangement of FIGS. 13A and 13B depict a singleaperture 16, aperture 16 may define three individual and separaterecesses 20. For example, a first recess 20A may be positioned along afirst portion of aperture 16, a second recess 20B may be positionedalong a second portion of aperture 16, and a third recess 20C may bepositioned along a third portion of aperture 16. Each recess 20 may beconfigured to receive a single screw 12 of the three screws 12.Additionally, similar to the arrangement of FIGS. 5A and 5B, a singleoffsetting element 24 may be positioned so as to cooperate with andassist in retaining each of the three screws 12. Accordingly, in such anarrangement, offsetting element 24 may be provided at a center ofaperture 16 and may include three convex portions 32 radiallyinterspersed between three concave portions 34, as shown. In an unlockedconfiguration, as shown in FIG. 13A, a first concave portion 34 may bepositioned adjacent to a first screw, a second concave portion 34 may bepositioned adjacent a second screw 12, and a third concave portion 34may be positioned adjacent a third screw 12. Further, each of the convexportions 32 may be positioned away or spaced from screws 12. Uponmovement or rotation of cam head 26 of the offsetting element 24 to thelocked or blocked configuration, as shown in FIG. 13B, convex portions32 are positioned adjacent apertures screws 12 while concave portions 34are positioned away or spaced from screws 12. In such a manner, a singleoffsetting element 24 may be used to simultaneously move and help retainthree separate screws 12 positioned in aperture 16.

Alternatively, instead of a single offsetting element 24 being includedso as to simultaneously move three separate screws 12 positioned inaperture 16, two or more offsetting elements 24 may be arranged relativeto aperture 16, as shown in FIGS. 14A and 14B. In such an arrangement,one or more of the three screws 12 may be moved towards the locked orblocked configuration independently of the remaining screws 12. Forexample, as shown in FIG. 14A, two offsetting elements 24 may bearranged relative to aperture 16. That is, a first offsetting element24A may be positioned adjacent a first screw 12 while a secondoffsetting element 24B may be positioned between the remaining twoscrews 12. In such a manner, the first screw 12 may be moved towards thelocked or blocked configuration independently of the second and thirdscrews 12. Further, the second and third screws 12 may movesimultaneously with one another while independent of the first screw 12towards the locked or blocked configuration. Alternatively, threeseparate and distinct offsetting elements 24 may be positioned relativeto aperture 16 such that each offsetting element 24 may be configured tocooperate with a single screw 12 of the three screws 12. In such amanner, each screw 12 may be moved independently of the other screws 12.

FIGS. 15 and 16 illustrate various modifications and arrangements ofillustrative examples in accordance with this disclosure. For example,as shown in FIG. 15, the substrate of interbody device 10 may define agenerally ovular or elongated aperture 16. As shown, aperture 16 maydefine three separate recesses 20, each configured to receive a singlescrew 12 therein. Accordingly, rather than in a generally triangularconfiguration as shown in FIGS. 13A, 13B, 14A, and 14B, aperture 16 mayreceive three screws 12 in a generally linear pattern. Further, asshown, two or more offsetting elements 24 may be arranged along aperture16. In such an arrangement, one or more of the three screws 12 may bemoved towards the locked or blocked configuration independently of theothers. For example, as shown in FIG. 15, two offsetting elements 24 maybe arranged along aperture 16. That is, a first offsetting element 24may be positioned adjacent a first screw 12 while a second offsettingelement 24 is positioned between the remaining two screws 12 of thethree screws 12. In such a manner, the first screw 12 may be movedtowards the locked or blocked configuration independently of the secondand third screws 12. Further, the second and third screws 12 may movesimultaneously with one another towards the locked or blockedconfiguration and independently of the first screw 12.

Alternatively, as shown in FIG. 16, the substrate of interbody device 10may define a generally non-linear aperture 16. For example, in thearrangement of FIG. 16, aperture 16 may have a generally L-shapedconfiguration. That is, aperture 16 may include two segments 17A and 17Bextending along intersecting axes. In some arrangements, an angle βbetween segments 17A and 17B may be about 90°. Those skilled in the artwill understand that angle β may be any appropriate angle. Accordingly,angle β may be any value greater or less than 90°. As shown, aperture 16may define two separate recess 20. A first recess 20 may be configuredto receive two screws 12 therein while a second recess may be configuredto receive a single screw 12 therein. Further, two or more offsettingelements 24 (not shown) may be arranged along aperture 16. In such anarrangement, one or more of the three screws 12 may be moved towards thelocked or blocked configuration independently of the others, asdiscussed above.

In a further example, as shown in FIG. 17, aperture 16 may be configuredto receive four screws 12 therein. That is, as shown in FIG. 17, asingle aperture 16 may be configured (e.g., sized) to receive fourscrews 12. While aperture 16 depicted in FIG. 17 includes a generallysquare and/or rectangular configuration with rounded corners, any otherappropriate shape configured to receive four screws 12 therein may beused, as will be described in further detail below.

Additionally, while the arrangement of FIG. 17 depicts a single aperture16, aperture 16 may define four individual and separate recesses 20. Forexample, a first recess 20 may be positioned along a first portion ofaperture 16, a second recess 20 may be positioned along a second portionof aperture 16, a third recess 20 may be positioned along a thirdportion of aperture 16, and a fourth recess 20 may be positioned along afourth portion of aperture 16. Each recess 20 may be configured toreceive a single screw 12 of the four screws 12. Additionally, similarto the arrangement of FIGS. 13A and 13B, a single offsetting element 24may be positioned so as to cooperate with and engage each of the fourscrews 12. Accordingly, in such an arrangement, offsetting element 24may be provided at a center of aperture 16 and may include four convexportions 32 interspersed with four concave portions 34 along anoutermost radial surface of offsetting element 24, as shown. In anunlocked configuration, as shown in FIG. 17, a first concave portion 34may be positioned adjacent to a first screw, a second concave portion 34may be positioned adjacent a second screw 12, a third concave portion 34may be positioned adjacent a third screw 12, and a fourth concaveportion 34 may be positioned adjacent a fourth screw 12. Further, eachof the convex portions 32 may be positioned away or spaced from screws12. Upon movement or rotation of cam head 26 of the offsetting element24 to the locked or blocked configuration (not shown), convex portions32 are positioned adjacent screws 12 while concave portions 34 arepositioned away or spaced from screws 12. In such a manner, a singleoffsetting element 24 may be used to simultaneously engage and retainfour separate screws 12 positioned in aperture 16.

Alternatively, instead of a single offsetting element 24 being includedso as to simultaneously move or otherwise bias four separate screws 12positioned in aperture 16, two or more offsetting elements 24 may bearranged about aperture 16. In such an arrangement, one or more of thefour screws 12 may be moved towards the locked or blocked configurationindependently of the others.

FIGS. 18-21 illustrate various modifications and arrangements ofillustrative examples in accordance with this disclosure. For example,as shown in FIG. 18, the substrate of interbody device 10 may define agenerally ovular or elongated aperture 16. As shown, aperture 16 definesfour separate recess 20, each configured to receive and retain a singlescrew 12 therein. Accordingly, instead of the generally square orrectangular configuration of FIG. 17, aperture 16 may receive fourscrews 12 in a generally linear pattern. As shown, the substrate ofinterbody device 10 as depicted in FIG. 18 may include four separate anddistinct recesses 20, each recess configured to receive a respective oneof four screws 12. However, as noted above, any appropriate number ofrecesses 20, such as 1, 2, 3, or 4, may be used. Though FIG. 18 depictseach of the four recesses 20 on a single side of aperture 16, one ormore of the recess 20 may be positioned along any of the other sides ofaperture 16. Additionally, although not shown in FIG. 18, anyappropriate number of offsetting elements 24 may be arranged alongaperture 16 so as to move one or more screws 12 towards the locked orblocked configuration. Alternatively, aperture 16 may have anyappropriate shape and/or rotational arrangement. For example, FIG. 19depicts a generally square-shaped aperture 16 having rounded corners,similar to FIG. 17, but rotated approximately 45°. Accordingly, aperture16 may be arranged such that screws 12 may be received along any desiredposition. Additionally, FIG. 20 illustrates a generallysinusoidally-shaped aperture 16, and FIG. 21 illustrates a generallynoncollinear shaped aperture 16. Although not shown in FIGS. 19-21, anyappropriate number of recesses 20 and offsetting elements 24 may beassociated with each aperture 16 so as to move each of the four screws12 towards the locked or blocked configuration.

A further exemplary system for preventing fixation devices such asscrews 12 from backing out (e.g., unscrewing) and/or dislodging frominterbody device 10 is shown in FIGS. 22A-22D. Similar to thearrangements described above, an exemplary interbody device 10 mayinclude a first face 14 defining an aperture 16 configured to receiveone or more screws 12 therein. For example, as shown in FIG. 22A,aperture 16 may be configured to receive two screws 12 therein. Aperture16 may have any appropriate shape configured to receive screws 12therein. For example, as shown in FIG. 22A, aperture 16 may be generallyelongated with rounded corners. Similar to the arrangements describedabove, and as shown in FIG. 22B, aperture 16 may include one or morerecesses 20 configured to cooperate with and/or correspond in profilewith head 18 of screw 12, so as to retain screw 12 within aperture 16.For example, as shown, aperture 16 may include two recesses 20, eachrecess 20 including a pocket or space into which head 18 of one of thetwo screws 12 may be moved upon the application of a lateral force. Oneof the recesses 20 may be disposed at a first location along aperture16, and the other recess 20 may be disposed at a second location alongaperture 16.

As shown, the substrate of interbody device 10 may further include anoffsetting element 24 similar to those described above. As shown in FIG.22A, offsetting element 24 may be positioned adjacent aperture 16 so asto cooperate with head 18 to prevent screw 12 from backing out (e.g.,unscrewing) or dislodging from interbody device 10. Further, offsettingelement 24 may be movably received within the substrate of interbodydevice 10. For example, in some arrangements, offsetting element 24 maybe rotatably received within the substrate of interbody device 10.

As shown in FIG. 22A, offsetting element 24 may include a cam head 26coupled to a shaft 28. Shaft 28 may extend into the substrate ofinterbody device 10 and include any appropriate threading or similarretention mechanism (not shown) configured to movably couple offsettingelement 24 to interbody device 10. Accordingly, interbody device 10 mayinclude an internally threaded bore for cooperation with shaft 28. Camhead 26 may include an actuator receiving element such as, for example,a hex-shaped bore 30 configured to cooperate with any appropriaterotatable driver (e.g., key, screw driver, hex driver, etc.). While bore30 is described and illustrated as a hex-shaped bore 30, it isunderstood that any appropriate shaped bore may be used so as tocooperate with any correspondingly shaped driver and/or driver tip. Camhead 26 may be eccentrically and/or irregularly shaped. For example, asshown, cam head 26 may include a crescent-shaped member have a convexportion 32 and a concave portion 34. In an unlocked configuration, asshown in FIG. 22A, concave portion 34 may be positioned adjacent toaperture 16 while convex portion 32 is positioned away or spaced fromaperture 16. Upon movement or rotation of cam head 26 to a locked orblocked configuration (FIG. 22D), convex portion 32 is positionedadjacent aperture 16 while concave portion 34 is positioned away orspaced from aperture 16.

FIGS. 22B-22D illustrate an exemplary manner of preventing screws 12from backing out (e.g., unscrewing) and/or dislodging from interbodydevice 10. For example, FIG. 22B illustrates interbody device 10 andoffsetting element 24 in the unlocked configuration. Accordingly, afirst screw 12 may be disposed into aperture 16, at a location distantor spaced from offsetting element 24, as shown in FIG. 22B. Next, asshown in FIG. 22C, second screw 12 may be inserted into aperture 16. Asshown, upon the insertion of second screw 12, first screw 12 may beurged or otherwise biased laterally toward a first recess 20. That is,interference between the first screw 12 and the second screw 12 maycause first screw 12 to be displaced laterally such that head 18 offirst screw 12 is received within or otherwise biased towards a firstrecess 20. Upon rotation of offsetting element 24, for example, indirection A as shown in FIG. 22D, cam head 26 of offsetting element 24may be rotated such that convex portion 32 may be brought in contactwith a side surface of head 18 of the second screw 12. As such, thesecond screw 12 may be pushed, moved, urged, or otherwise urgedlaterally toward the second recess 20 and the external side and/or topsurface of head 18 of screw 12 may be received within recess 20.Accordingly, in the locked or blocked configuration, as shown in FIG.22D, offsetting element 24 may be configured to retain screw 12 ininterbody device 10.

It is to be understood, that any one or more of the previously disclosedfeatures of interbody device 10 may be used together or separately. Forexample, the substrate of interbody device 10 may define one or moreapertures 16 therein. Each aperture may be configured (e.g., sized) tofit one or more screws 12 therein. Additionally, each aperture 16 mayinclude one or more recesses 20 therein. That is, in some arrangements,a single recess 20 may be configured to receive one or more screws 12therein. Additionally, as noted above, any appropriate configuration ofaperture(s) may be provided. For example, in some arrangements,aperture(s) 16 may have a substantially constant width. As used herein,the terms “about,” “substantially,” and “approximately,” may indicate arange of values within +/−5% of a stated value. Alternatively, in somearrangements, aperture(s) may have a varied width. Additionally,aperture(s) 16 may be arranged in a linear, nonlinear, and/orsymmetrical configurations. In some arrangements, aperture(s) 16 may bearranged in a general oval, triangle, and/or square configuration.Additionally, in examples in which multiple screws 12 are receivedwithin a single aperture 16, aperture 16 may be configured such that agap G is provided between adjacent side surfaces of screws 12, oralternatively, such that no gap G is provided between adjacent sidesurfaces of screws 12. Further, as discussed above, in any disclosedarrangement, one or more offsetting elements 24 may be arranged alongaperture(s) 16 at any suitable location. In some arrangements, a singleoffsetting element 24 may be provided to assist in retaining one, two,three, four, or more screws 12 from the unlocked configuration to thelocked or blocked configuration simultaneously. Alternatively, multipleoffsetting elements 24 may be provided such that one or more screws 12may be independently moved from the unlocked configuration to the lockedor blocked configuration.

Screws 12 may have any appropriate geometry and/or configuration. Forexample, head 18 of each screw 12 may be either a fixed-angle screw heador variable angle screw head depending on the required conicalangulation of screw 12. For example, in some arrangements, the conicalangulation of screw 12 may be between about 0° and 20°. In somearrangements, the conical angulation of screw 12 may be about 15°.Additionally, screws 12 may be either self-drilling or self-tapping.Screws 12 may have any appropriate thread length and thread diameter.For example, screws 12 may have a thread length between about 8 mm and65 mm. That is, screws 12 may have a thread length between about 8 mmand 25 mm, between about 15 mm and 45 mm, and/or about 25 mm and 65 mm.Screws 12 may have a thread diameter between about 3 mm and 6.5 mm. Forexample, screws 12 may have a thread diameter between about 3 mm and 4.5mm, and/or between about 4.5 mm and 6.5 mm.

Interbody Device Structure and Features

FIGS. 23-32 schematically illustrate various configurations of exemplaryinterbody devices 10 (e.g., a cage, spacer, and/or block). Indeed, FIGS.23-27 illustrate exemplary standalone interbody devices 10 and FIGS.28-32 illustrate exemplary composite interbody devices 10. Standaloneinterbody devices 10 may include any structure configured to acceptscrews 12 directly therethrough, whereas composite interbody devices 10may include any combination of a plate and spacer/cage, collectivelyconfigured to accept screws 12 therethrough.

Standalone interbody devices 10 may include any appropriateconfiguration. For example, as shown in FIG. 23, interbody device 10 maydefine a closed cage. That is, interbody device 10 may include agenerally rectangular and/or square shape having at least four sides 50.Accordingly, interbody device 10 may define an internal space 52surrounded on four sides thereof by sides 50. Space 52 may be configuredto receive bone graft or other suitable ingrowth promoting material.Additionally, at least one side 50 may define a screw receiving face 14including one or more apertures 16, as discussed above.

Alternatively, interbody device 10 may define an open cage having threesides 50. For example, in some arrangements, as shown in FIG. 24,interbody device 10 may have an open front and include two lateral sides50 connected by one rear side 50. In other arrangements, as shown inFIG. 25, interbody device 10 may have an open rear and include twolateral sides 50 connected by one front side 50. Alternatively, as shownin FIG. 26, interbody device 10 may have an open lateral side, andinclude one lateral side 50, one rear side 50, and one front side 50. Inyet a further arrangement, as shown in FIG. 27, interbody device 10 mayinclude a closed cage having an enlarged front side 50. Such an enlargedfront side 50 may facilitate placement of screws 12 at varied heightsalong spinal column 2.

Similar to standalone interbody devices 10, composite interbody devices10 may include any appropriate configuration. For example, as shown inFIG. 28, interbody device 10 may include a closed cage. That is,interbody device 10 may include a generally rectangular and/or squarecage having at least four sides 50 which may define an internal space52. Additionally, interbody device 10 may include a panel (e.g., plate)54 defining a screw receiving face 14 including one or more apertures16, as discussed above. Panel 54 may be coupled to the cage of interbodydevice 10 via any appropriate manner such as, for example, welding,fusion, adhesives or the like.

In another arrangement, as shown in FIG. 29, interbody device 10 maydefine an open cage having three sides. For example, in somearrangements, as shown in FIG. 29, the cage of interbody device 10 mayhave an open front and include two lateral and one rear side 50.Additionally, interbody device 10 may further include a panel 54defining a screw receiving face 14 including one or more apertures 16.In other arrangements, as shown in FIG. 30, interbody device 10 mayinclude an open cage having an open rear and two lateral and one frontsides 50. Alternatively, as shown in FIG. 31, interbody device 10 mayinclude a cage having an open lateral side, and one lateral, one rear,and one front side 50. In yet a further arrangement, as shown in FIG.32, interbody device 10 may include an closed cage. Additionally, asshown, panel 54 may be enlarged relative to the cage. Such an enlargedpanel 54 may facilitate placement of screws 12 at varied heights alongspinal column 2. Exemplary interbody devices 10 may include ahomogeneous stainless steel, titanium, chromium, PEEK, and/orcombinations thereof. Alternatively, exemplary interbody devices 10 mayinclude a heterogeneous composite such as PEEK embedded with radiopaquemixtures so as to provide different gradients of radio-opacity, as willbe described in further detail below. For example, in some arrangements,interbody device 10 may be comprised of a substantially radiolucentmaterial such as PEEK. To enable visual inspection of such an interbodydevice 10 via X-ray or other such imaging modalities, interbody device10 may additionally include a pin, screw, or other such member comprisedof a radiopaque material. For instance, in some arrangements, such a pinor screw may be comprised of tantalum. Additionally, any one ofinterbody devices 10 of FIGS. 23-32 may include any of the featuresnoted above. That is, any of interbody devices 10 discussed throughoutthis disclosure may include any one or more of offsetting elements 24configured to facilitate locking or blocking one or more screws 12,disposed in one or more aperture 16, from backing out (e.g., unscrewing)and/or dislodging from interbody device 10. Additionally, exemplaryinterbody devices 10 may be solid, or in some arrangements, may beformed through any appropriate manufacturing method so as to begenerally porous while remaining structurally strong. For example, inarrangements, one or more portion of interbody device 10 may be thinnedor reduced in profile.

For example, as shown in FIG. 33, interbody device 10 may include a face14 defining two apertures 16 and having an offsetting element 24 (or anyother screw blocking mechanism) therebetween. Offsetting element 24 maybe similar in construction and manner of use as described above.Further, various arrangements of interbody devices 10 may include one ormore features configured to facilitate sagittal and/or coronalvisibility. For example, a body or frame 60 of interbody device 10 maycomprise a radiopaque material visible via x-ray or similar forms ofimaging modalities. As such, frame 60 may enable accurate positioningand/or placement of interbody device 10 within and/or along spinalcolumn 2. Frame 60 may include any one or more features such asanti-migration and/or anchoring features, anti-rotation features,insertion tool features, reduced profile keel features, and the like, aswill be described in further detail below.

Additionally, frame 60 may define one or more openings and/or windows62. Such windows 62 may remain empty and/or may be filled withradiolucent material such as tissue grafts as will be described infurther detail below. Window(s) 62 may enable a medical professional toview and/or determine the level of post-operative fusion betweeninterbody device 10 and patient bone and/or tissue. Frame 60 may defineany appropriate arrangement, number, and configuration of window(s) 62.That is, as shown in FIG. 33, for example, interbody device 10 maycomprise a standalone device having a closed cage, similar to thearrangement of FIG. 23. As shown in FIG. 33, frame 60 may include asingle window 62 on each lateral side 50 and rear side 50. Each window62 may be generally square or rectangular. In some arrangements, aradiolucent structure, such as a graft containment sheath, may bedisposed along one or more portions of frame 60, as will be described infurther detail below. Indeed, such graft containment sheaths maysubstantially fill or encompass window 62 of one or more sides 50 offrame 60. Accordingly, in the sagittal view of interbody device 10placed between two adjacent vertebrae 4 under X-ray vision, as shown inFIG. 34, window 62 remains radiolucent such that fusion within and/orthrough window 62 may be observed.

In other arrangements, frame 60 of interbody device 10 may define one ormore split windows 62. As shown in FIG. 35, for example, interbodydevice 10 may comprise a standalone device having a closed cage, similarto the arrangement of FIG. 23. Rather than solid panel lateral sides 50,frame 60 may include lateral supports 64 defining a first (e.g., upper)window portion 62A and a second (e.g., lower) window portion 62B.Accordingly, in the sagittal view of interbody device 10 placed betweentwo adjacent vertebrae 4 under X-ray vision, as shown in FIG. 36, firstwindow portion 62A and second window portion 62B remain radiolucent suchthat fusion within and/or through first window portion 62A and secondwindow portion 62B may be observed.

Alternatively, as shown in FIG. 37, a composite interbody device 10 mayinclude a panel 54 defining a screw receiving face 14 including one ormore apertures 16, as discussed above. Panel 54 may define a pair ofopposed lateral arms 56 extending therefrom. Panel 54 may be coupled toa radiolucent cage portion 58. Cage portion 58 may include anyappropriate radiolucent structure configured to maintain a desiredspacing between adjacent vertebrae 4. Accordingly, cage portion 58 maybe any non-metallic structure extending from panel 54 and may, in somearrangements, include a graft containment sheath, as will be describedin further detail below. In the sagittal view of interbody device 10placed between two adjacent vertebrae 4 under Xray vision, as shown inFIG. 38, a generally inverted c-shaped window 62 may remain radiolucentsuch that fusion within and/or through window 62 may be observed.

Alternatively, as shown in FIGS. 39-41, a composite interbody device 10may include a panel 54 defining a screw 12 receiving face 14 includingone or more apertures 16 configured to receive a screw 12 (or similarfastener) therein, as discussed above. Panel 54 may be coupled to aradiolucent cage portion 58. Cage portion 58 may include any appropriateradiolucent structure configured to maintain a desired spacing betweenadjacent vertebrae 4. Accordingly, cage portion 58 may be anynonmetallic structure extending from panel 54 and may in somearrangements include a graft containment sheath, as will be described infurther detail below. Cage portion 58 may include any appropriatestructure, geometry, and/or feature(s) configured to couple with panel54. In the sagittal view of interbody device 10 placed between twoadjacent vertebrae 4 under X-ray vision, as shown in FIG. 41, agenerally square and/or rectangle shaped window 62 may remainradiolucent such that fusion within and/or through window 62 may beobserved.

As discussed above, any of the above noted windows 62, first windowportion 62A, and/or second window portion 62B may be filled withradiolucent material such as tissue grafts. That is, as shown in FIG.42, a representative interbody device 10 may be packed with bone graft.For example, internal space 52 of frame 60 may be filled with packedbone graft material 70. Bone graft material 70 may facilitate bone andtissue ingrowth in and through interbody device 10. Accordingly, bonegraft 70 may promote fusion, i.e., the joining of two or more vertebrae4. However, during placement of interbody device 10 within spinal column2 and/or manipulation thereafter, bone graft material 70 may becomedislodged and/or fall out of interbody device 10 via the windows 62.Additionally, inclusion of one or more windows 62 may further enablebone graft material 70 to dislodge from and/or fall out of interbodydevice 10. Accordingly, as shown in FIG. 43, interbody device 10 mayinclude one or more retention members 72 configured to retain bone graftmaterial 70 within interbody device 10. In some arrangements, retentionmembers 72 may be radiolucent. Radiolucent retention member(s) 72 mayfunction to prevent bone graft material 70 from passing through, e.g., awindow 62 without impeding visibility through window 62. For example,retention members 72 may include any one or more of a panel, screen,skin, and/or scaffold. In some arrangements, retention members 72 may beintegrally and monolithically formed of a one-piece construction withinterbody device 10. Alternatively, however, interbody device 10 maydefine one or more reception spaces 74 configured (e.g., sized andshaped) to receive one or more retention members 72 therein. As shown inFIG. 43, reception space(s) 74 may include a narrow slot, groove, slit,aperture, and/or opening within frame 60 of interbody device 10. Asshown, reception spaces 74 may receive and hold one or more retentionmembers 72 therein.

Additionally or alternatively, retention members 72 may include any ofinterbody device 10 geometry, serrations, teeth, keels, mesh, beams, andsimilar structures configured to retrain bone graft material 70 withininterbody device 10. Indeed, FIGS. 44-49 illustrate cross-sectionalviews of exemplary interbody devices 10 taken along line X-X of FIG. 42,and further including various configurations of retention members 72.For example, as shown in FIG. 44, an exemplary retention member 72 mayinclude a mesh screen 76 extending within a center opening of interbodydevice 10. Alternatively, as shown in FIG. 45, retention member 72 mayinclude one or more bars, wires, and/or beams 78 extending substantiallyacross a center opening of interbody device 10. Similarly, as shown inFIG. 46, retention member 72 may include one or more beam protrusions 80extending partially across a center opening of interbody device 10. Inyet a further arrangement, as shown in FIG. 47, retention member 72 mayinclude one or more serrations 82 extending in a center opening ofinterbody device 10. Serrations 82 may have any suitable configuration.In some arrangements, serrations 82 may include substantially similarconfigurations. In other arrangements, however, each serration ofserrations 82 may have unique configurations. For example, as shown inFIG. 47, a first set of serrations 82 may be oriented in a firstdirection while a second set of serrations 82 may be oriented in asecond direction, different than the first direction. Any of mesh 76,beams 78, beam protrusions 80, and/or serrations 82 may be positionedalong any one or more of a bottom face, top face, any plane extendingbetween a top and bottom face, lateral side, rear face, and/or frontface of interbody device 10.

Further, as noted above, an internal geometry of interbody device 10 maybe configured such that bone graft material 70 packed within interbodydevice 10 may be retained therein. That is, interior surface(s) ofinterbody device 10 may define one or more non-uniform or unevensurfaces which, upon receipt of packed bone graft material 70, may actto hold bone graft material 70 therein. For example, as shown in FIG.48, inner walls of interbody device 10 may define a wall recess 84.Alternatively, as shown in FIG. 49, inner walls of interbody device 10may define a wall concavity 86. Wall recess 84 and/or wall concavity 86may be configured to receive and retain bone graft material 70 therein.

As noted above, interbody device 10 may include one or more featuressuch as anti-migration and/or anchoring features, anti-rotationfeatures, insertion tool features, reduced profile keel features, andthe like. For example, interbody device 10 may include one or morefeatures configured to maintain interbody device 10 within a desiredposition within spinal column 2. Such features may include one or moreof notches, bumps, tangs, grips, and/or protrusions 90 extending from anouter surface of frame 60 of interbody device 10. Protrusions 90 mayinclude any appropriate configuration, such as, for example, triangular(FIG. 50), pyramidal (FIG. 51), conical and/or irregular shapes.Further, it is understood that any combination of geometric shapesand/or arrangement of protrusions 90 may be disposed along any surfaceof interbody device 10.

Further, as shown in FIGS. 52 and 53, exemplary interbody devices 10 mayinclude one or more recessed keels. For example, frame 60 of interbodydevice 10 (or panel 54 of a composite interbody device 10), may includea tapered and/or angled keel feature 94 as shown in FIG. 52. That is,keel feature 94 may include an extension having an anterior surface 96angled relative to an anterior-most surface 98 of interbody device 10.For example, as shown, surface 96 may extend at an angle α relative tosurface 98. In some arrangements, angle α may be between about 0° andabout 45°. As shown, keel feature 94 may be offset or spaced fromanterior-most surface 98 of interbody device 10. In other words, keelfeature 94 may be spaced away from an anterior-most surface 98 by asubstantially planar wall portion 98 c which extends perpendicularly toanterior-most surface 98. The angled arrangement of keel feature 94 mayprevent interbody device 10 from inadvertently dislodging from spinalcolumn 2 after placement between two adjacent vertebra 4. For example,keel feature 94 may enable movement in a first direction along the Zaxis (FIG. 2) while preventing and/or deterring movement in a seconddirection along the Z axis. That is, keel feature 94 may facilitaterelatively easier insertion of interbody device 10 between adjacentvertebrae while preventing or inhibiting removal of interbody device 10.Additionally, due to the angled configuration of keel feature 94, keelfeature 94 may be recessed from surface 98 so as to minimize potentialexposure and/or irritation of surrounding tissue and/or bone byinterbody device 10. Accordingly, keel feature 94 may facilitate azero-profile (or minimal-profile) arrangement of interbody device 10.

In a further arrangement, as shown in FIG. 53, for example, surface 96may extend in a direction generally parallel to surface 98 while aposterior-facing surface 100 of keel feature 94 may be angled relativeto surface 98. In this arrangement, keel feature 94 may enable movementin the second direction along the Z axis (FIG. 2) while preventingand/or deterring movement in the first direction along the Z axis. FIG.54 illustrates an exemplary interbody device 10, having a recessed keelfeature 94, positioned within spinal column 2 and engaging the endplatesof adjacent vertebrae 4. Specifically, upon placement of interbodydevice 10 between adjacent vertebrae 4, keel feature(s) 94 may beembedded within vertebrae 4 and as such, prevent movement in at leastone direction along the Z axis. Additionally, since keel feature 94 isrecessed, keel feature 94 may be prevented from contacting, damaging,and/or irritating surrounding tissue.

FIGS. 55 and 56 illustrate a front and side view of an exemplaryinterbody device 10, including features described above. For example, asshown in FIG. 55, interbody device 10 may include a frame 60, and in thecase of a composite interbody device 10 (as shown in FIGS. 28-32),interbody device 10 may further include a panel 54 coupled to frame 60.Frame 60 may include any of the screw blocking mechanisms discussedabove. For example, frame 60 and/or panel 54 may include one or moreapertures 16 and an offsetting element 24 therebetween. Offsettingelement 24 may be similar in construction and manner of use as describedabove. Additionally, interbody device 10 may include any one or moreprotrusions 90 configured to maintain interbody device 10 within adesired position within adjacent vertebrae 4. Such protrusions may bepositioned along any appropriate portion of interbody device 10, suchas, for example, an upper and lower surface of interbody device 10.Interbody device 10 may additionally include a recessed keel feature 94as discussed above. Additionally, as shown in FIG. 56, interbody device10 may include one or more instrumentation grooves, pockets, holes,and/or notches 110. Notches 110 may have any appropriate shape and/orarrangement to facilitate manipulation of interbody device 10 via a toolor other instrument during insertion, positioning, or manipulation ofinterbody device by a medical professional. That is, notches 110 mayfacilitate quick grasping of interbody device 10 via an appropriate tool(e.g., forceps or the like).

FIGS. 57-60 illustrate exemplary features of a disclosed interbodydevice 10, including various features discussed above. Indeed, FIG. 57schematically illustrates interbody device 10 positioned between twoadjacent vertebrae 4. As noted above, each vertebra 4 includes spongycancellous bone 112 which is then covered by a thin coating of corticalbone 114. As shown in FIG. 57, when one or more screws 12 are inserteddirectly through interbody device 10 into vertebra 4, a portion of screw12 may extend through interbody device 10, through cortical bone 114,and terminate within cancellous bone 112, which may facilitateosteogenesis.

FIG. 58 is a perspective view of interbody device 10. As shown,interbody device 10 may include a frame 60 including any of the screwblocking mechanisms discussed above. For example, frame 60 may includeone or more apertures 16 and an offsetting element 24 therebetween.Offsetting element 24 may be similar in construction and manner of useas described above. Additionally, interbody device 10 may include anyone or more protrusions 90 configured to maintain interbody device 10within a desired position within spinal column 2. Additionally,interbody device 10 may include a recessed keel feature 94 and one ormore notches 110 as discussed above. Still further, interbody device 10may include a graft containment sheath 120. Graft containment sheath 120may be disposed along one or more portions of frame 60. For example,graft containment sheath 120 may be wrapped around frame 60 and maysubstantially cover or encompass windows 62 (FIG. 59) of frame 60. Thatis, graft containment sheath 120 may be configured so as to cooperatewith frame 60 of interbody device 10 such that bone graft material 70may be retained within interbody device 10 so as to facilitate fusion.As shown in FIG. 60, once interbody device 10, including graftcontainment sheath 120, is positioned within spinal column 2, screws 12may be extended through apertures 16 and into vertebra 4 (e.g., throughend plates of each vertebrae 4) so as to secure adjacent vertebrae 4relative to one another.

FIGS. 61-63 illustrate exemplary features of a further disclosedinterbody device 10, including various features discussed above. FIG. 61is a perspective view of interbody device 10. As shown, interbody device10 may include a frame 60 including any of the screw blocking mechanismsdiscussed above. For example, frame 60 may include one or more apertures16 and an offsetting element 24 therebetween. Offsetting element 24 maybe similar in construction and manner of use as described above. Asshown in FIG. 62, frame 60 may include lateral supports 64 definingfirst (e.g., upper) window portion 62A and a second (e.g., lower) windowportion 62B. Additionally, interbody device 10 may include one or moreprotrusions 90 configured to maintain interbody device 10 within adesired position within spinal column 2. Additionally, interbody device10 may include a recessed keel feature 94 and one or more notches 110 asdiscussed above. Still further, interbody device 10 may include a graftcontainment sheath 120. Graft containment sheath 120 may be disposedalong one or more portions of frame 60. For example, graft containmentsheath 120 may be wrapped around frame 60 and may substantially cover orencompass first and second window portions 62A and 62B of frame 60. Thatis, graft containment sheath 120 may be configured so as to cooperatewith frame 60 of interbody device 10 such that bone graft material 70may be retained within interbody device 10 so as to facilitate fusion.As shown in FIG. 63, once interbody device 10, including graftcontainment sheath 120, is positioned within spinal column 2, screws 12may be extended through apertures 16 and into vertebrae 4 (e.g., throughend plates of each vertebra 4) so as to secure adjacent vertebraerelative to one another. In some arrangements, graft containment sheath120 may be made of a radiolucent material such as, e.g., PEEK.

FIGS. 64 and 65A-C illustrate a further arrangement of interbody device10 including exemplary features described above. For example, as shownin FIG. 64, interbody device 10 may include an aperture 16 configured toreceive four screws 12 therein. As described above in connection withFIG. 17, aperture 16 may include a first recess 20 positioned along afirst portion of aperture 16, a second recess 20 positioned along asecond portion of aperture 16, a third recess 20 positioned along athird portion of aperture 16, and a fourth recess 20 positioned along afourth portion of aperture 16. Each recess 20 may be configured toretain a single screw 12 of the four screws 12. Additionally, as shownin FIG. 64, a screw blocking mechanism (such as, e.g., an offsettingelement 24) may be positioned so as to cooperate with each of the fourscrews 12. Accordingly, in such an arrangement, offsetting element 24may be provided at a center of aperture 16.

Additionally, interbody device 10 may include a graft containment sheath120. Graft containment sheath 120 may be disposed along one or moreportions of frame 60. For example, graft containment sheath 120 may bewrapped around frame 60 such that bone graft material 70 may be retainedwithin desired portions of interbody device 10 so as to facilitatefusion.

As shown in FIG. 64, frame 60 may provide one or more windows 62 along acoronal plane of interbody device 10, as will be described in furtherdetail below Further, as shown in FIG. 65A, frame 60 may be bent,angled, or otherwise arranged so as to correspond in profile to spinalcolumn 2. That is, at least the anterior-most surface 98 of frame 60 maybe angled so as to be recessed relative to one or more vertebrae 4(shown in phantom lines) of spinal column 2. Additionally oralternatively, as shown in FIGS. 65B and 65C, frame 60 may include ahinge 63 such that frame 60 may be selectively angled to accommodatevarious anatomies of spinal column 2. For example, a longitudinal axisof at least a first (e.g., posterior) portion 60A of frame 60 may beoriented at an angle α relative to a longitudinal axis of at least asecond (e.g., anterior) portion 60B of frame 60, as shown in phantom inFIG. 65B. Angle σ may be any appropriate angle. For example, angle σ maybe between about 0° and about 90°. In some arrangements, angle σ may beabout 45°. In such a manner, frame 60 may be arranged in any appropriateorientation so as to correspond to spinal column 2. For example, frame60 may be arranged in any appropriate orientation either externally ofthe body of the patient, or after insertion within spinal column 2. Ineither arrangement, a medical professional may insert a tool (e.g., awedge) to articulate second portion 60B relative to first portion 60A offrame 60. In some arrangements, hinge 63 may include a selectivelyactuatable lock (not shown), such that, once activated or locked, frame60 may maintain a desired angle. Additionally, once de-activated orunlocked, frame 60 may again be readjusted along any appropriate angle.

As noted above, frame 60 may provide one or more windows 62 along acoronal plane of interbody device 10. Accordingly, in the coronal viewof interbody device 10 placed between two adjacent vertebrae 4 underX-ray vision, as shown in FIG. 66, windows 62 remains radiolucent suchthat fusion within and/or through windows 62 may be observed.Additionally, as shown in FIG. 67, frame 60 may define one or morewindows 62 along the sagittal plane of interbody device 10. Accordingly,in the sagittal view of interbody device 10 placed between two adjacentvertebrae 4 under X-ray vision, as shown in FIG. 67, windows 62 remainradiolucent such that fusion within and/or through windows 62 may beobserved. It is understood that coronal plane windows 62 may be includedin any of the interbody device 10 structures noted above, and windows 62may have any suitable configuration. For example, in an arrangement inwhich interbody device 10 is configured to receive two screws 12, frame60 may define one or more coronal plane windows 62 therein. Accordingly,in the coronal view of interbody device 10 placed between two adjacentvertebrae 4 under X-ray vision, as shown in FIG. 68, windows 62 remainradiolucent such that fusion within and/or through windows 62 may beobserved.

FIG. 69A illustrates spinal column 2 having a plurality of interbodydevices 10 disposed between vertebrae 4 (shown in phantom lines). Asshown, each the plurality interbody devices 10 may be arranged along acentral longitudinal axis (e.g., axis Y of FIG. 2) within a commonplane. That is, one or more of screws 12 extending through one or moreinterbody devices 10 may be positioned along the central longitudinalaxis Y in a common plane (e.g., screws 12 through a first interbodydevice 10A of FIG. 69A positioned so as to be aligned along axis Y).Additionally or alternatively, one or more screws 12 extending throughone or more interbody device 10 may be positioned on a common plane andspaced (either equidistantly or nonequidistantly) from centrallongitudinal axis Y (e.g., screws 12 through second interbody device 10Bof FIG. 69A). Additionally or alternatively, one or more screws 12extending through one or more interbody devices 10 may be positionedsuch that some are positioned along the central longitudinal axis Ywhile others are spaced (either equidistantly or non-equidistantly) fromcentral longitudinal axis Y along a common plane (e.g., screws 12through second interbody device 10C of FIG. 69A).

For example, a first interbody device 10A may be disposed betweenadjacent vertebrae 4. A perspective view of first interbody device 10A,without screws 12, is shown in FIG. 69B. As shown in FIG. 69A, firstinterbody device 10A may be configured to receive two screws 12. Assuch, first interbody device 10A may include a frame 60 including any ofthe screw blocking mechanisms discussed above. For example, frame 60 mayinclude one or more apertures 16 and an offsetting element 24therebetween. Offsetting element 24 may be similar in construction andmanner of use as described above. Frame 60 may define one or morewindows 62 along a coronal plane of first interbody device 10A.Accordingly, in the coronal view of first interbody device 10A placedbetween two adjacent vertebrae 4 under X-ray vision, as shown in FIG.69A, windows 62 remain radiolucent such that fusion within and/orthrough window 62 may be observed. Optionally, first interbody device10A may include a graft containment sheath 120. Graft containment sheath120 may be disposed along one or more portions of frame 60. For example,graft containment sheath 120 may be wrapped around frame 60 and maysubstantially fill or encompass windows 62 of frame 60. That is, graftcontainment sheath 120 may be configured so as to cooperate with frame60 of first interbody device 10A such that bone graft material 70 may beretained within desired portions of first interbody device 10A so as tofacilitate fusion.

Further, as shown in FIG. 69A, a second interbody device 10B may bedisposed between adjacent vertebrae 4. A perspective view of secondinterbody device 10B, without screws 12, is shown in FIG. 69C. As shownin FIG. 69A, second interbody device 10B may be configured to receivefour screws 12. As such, second interbody device 10B may include a frame60 including any of the screw blocking mechanisms discussed above. Forexample, frame 60 may include one or more apertures 16 and an offsettingelement 24 therebetween. Offsetting element 24 may be similar inconstruction and manner of use as described above. Frame 60 may defineone or more windows 62 along a coronal plane of second interbody device10B. Accordingly, in the coronal view of second interbody device 10Bplaced between two adjacent vertebrae 4 under X-ray vision, as shown inFIG. 69A, windows 62 remain radiolucent such that fusion within and/orthrough window 62 may be observed. Optionally, second interbody device10B may include a graft containment sheath 120. Graft containment sheath120 may be disposed along one or more portions of frame 60. For example,graft containment sheath 120 may be wrapped around frame 60 and maysubstantially fill or encompass windows 62 of frame 60. That is, graftcontainment sheath 120 may be configured so as to cooperate with frame60 of second interbody device 10B such that bone graft material 70 maybe disposed along desired portions of second interbody device 10B so asto facilitate fusion.

Additionally, as shown in FIG. 69C, a third interbody device 10C may bedisposed between adjacent vertebra 4. A perspective view of thirdinterbody device 10C, without screws 12, is shown in FIG. 690. As shownin FIG. 69A, third interbody device 10C may be configured to receivethree screws 12. As such, third interbody device 10C may include a frame60 including any of the screw blocking mechanisms discussed above. Forexample, frame 60 may include one or more apertures 16 and an offsettingelement 24 therebetween. Offsetting element 24 may be similar inconstruction and manner of use as described above. Frame 60 may defineone or more windows 62 along a coronal plane of third interbody device10C. Accordingly, in the coronal view of third interbody device 10Cplaced between two adjacent vertebrae 4 under X-ray vision, as shown inFIG. 69A, windows 62 remain radiolucent such that fusion within and/orthrough window 62 may be observed. Optionally, third interbody device10C may include a graft containment sheath 120. Graft containment sheath120 may be disposed along one or more portions of frame 60. For example,graft containment sheath 120 may be wrapped around frame 60 and maysubstantially fill or encompass windows 62 of frame 60. That is, graftcontainment sheath 120 may be configured so as to cooperate with frame60 of third interbody device 10C such that bone graft material 70 may beretained within desired portions of third interbody device 10C so as tofacilitate fusion.

As shown in FIG. 69A, a screw 12 extends through first interbody device10A toward second interbody device 10B and into vertebra 4, and screws12 extend through second interbody device 10B toward first interbodydevice 10A and into the same vertebra 4 may be spaced from one another.That is, screws 12 may be arranged and/or oriented so as not tointerfere with one another as each passes through a respective interbodydevice 10 and into vertebra 4. Indeed, screw 12 extending through firstinterbody device 10 and into vertebra 4 may be received within vertebra4 between screws 12 extending through second interbody device 10B andinto vertebra 4. Likewise, screws 12 extending through second interbodydevice 10B toward third interbody device 10C and into vertebra 4, andscrews 12 extending through third interbody device 10C toward secondinterbody device 10B and into the same vertebra 4 may be spaced from oneanother. Accordingly, first interbody device 10A, second interbodydevice 10B, and third interbody device 10C may be stacked along spinalcolumn 2 without interfering with one another. In such a manner,multiple portions of spinal column 2 may be treated simultaneously. Itis understood that first interbody device 10A, second interbody device10B, and third interbody device 10C are merely representative and anyarrangement of interbody devices 10 may be stacked along spinal column2. Accordingly, any appropriate arrangement of any of the abovedisclosed interbody devices 10 may be arranged along spinal column 2 soas to produce any desired therapeutic effect.

As noted above in connection with FIG. 27, a standalone interbody device10 may include a closed cage having an enlarged front side 50. Such anenlarged front side 50 may facilitate placement of screws 12 at variedheights along spinal column 2. Alternatively, as noted above inconnection with FIG. 32, a composite interbody device 10 may include aclosed cage coupled to a panel 54 enlarged relative to the cage. Such anenlarged panel 54 may also facilitate placement of screws 12 at variedheights along spinal column 2. Additionally, in some examples, panels 54may be used alone without a cage coupled thereto. In any sucharrangement, as shown in FIGS. 70-75, an enlarged front side 50 and/orpanel 54 may include any appropriate shape. By way of example only,FIGS. 70-78E will be described in connection with a composite interbodydevice 10 including panel 54. It is understood, however, that thefeatures described below may likewise be employed in a standaloneinterbody device 10.

For example, as shown in FIGS. 70 and 71, panel 54 may be generallysymmetric about the X and Y planes of spinal column 2 (FIG. 2). That is,panel 54 may be generally rectangular or square. In some arrangements,as shown in FIG. 70, panel 54 may define one or more apertures 16, eachconfigured to receive a screw 12 therethrough. Alternatively, as shownin FIG. 71, panel 54 may define one or more apertures 16 each configuredto receive a screw 12 therethrough. In either arrangement, a first halfof screws 12 may extend through panel 54 and into a first vertebra 4while a second half of screws 12 may extend through panel 54 into asecond, adjacent vertebra 4. Alternatively, as shown in FIGS. 72-75,panel 54 may be asymmetric about one or both of the X and Y planes ofspinal column 2. For example, as shown in FIG. 72, panel 54 may begenerally triangular with rounded corners or apices. Panel 54 may defineone or more apertures 16 configured to receive three screwstherethrough. Accordingly, a first screw 12 may extend through panel 54and into a first vertebra 4 while second and third screws 12 may extendthrough panel 54 into a second vertebra 4. Alternatively, as shown inFIG. 73, panel 54 may define a general buttress shape. Accordingly,panel 54 may define one or more apertures 16 each configured to receivea screw 12 therethrough, each of which may extend through panel 54 intoa common vertebra 4. In an additional embodiment, as shown in FIG. 74,panel 54 may be generally s-curved. Panel 54 may define one or moreapertures 16 each configured to receive a screw 12 therethrough.Accordingly, a first screw 12 may extend through panel 54 and into afirst vertebra 4 while a second screw 12 may extend through panel 54into a second, adjacent vertebra 4. As shown in each of FIGS. 70-74,each screw 12 may be configured to extend directly through an anteriorsurface of vertebra 4. In other arrangements, as shown in FIG. 75, oneor more screws 12 may be configured so as to extend through an edge ofvertebra 4. That is, panel 54 may be shortened relative to panel 54 ofFIGS. 70-74. Accordingly, one or more screws 12 extending though panel54 may be arranged so as to enter vertebra 4 through an edge thereof. Itis understood that such a shortened panel 54 may be used for any of thearrangements of FIGS. 70-74 without departing from the scope of thisdisclosure. Accordingly, any one or more of screws 12, of any disclosedarrangement, may be configured so as to extend through an edge ofvertebra 4. Additionally, it is understood that each aperture 16 may beencircled on all sides thereof by panel 54 thus forming a closed loopaperture 16, as shown in FIG. 76. Alternatively, however, one or moreapertures 16 defined by panel 54 may be open loop apertures. That is,aperture 16 may extend to an edge of panel 54 such that one or morescrews 12 may be received therethrough. Accordingly, panel 54 may notencircle aperture 16 on all sides thereof, as shown in FIG. 77.

Additionally, while FIGS. 70-75 illustrate arrangements in which panel54 is coupled to two adjacent vertebrae 4, the disclosure is not solimited. Rather, panels 54 may be configured so as to be coupled to morethan two vertebrae 4. That is, panels 54 may be multi-level panels 54spanning a plurality of vertebrae 4. For example, FIGS. 78A-78Eillustrate exemplary arrangements of panel 54 coupled to any of 2, 3, 4,5, and/or 6 vertebra 4. Panels 54 may be similar to those describedabove, and may include any appropriate number of aperture 16 forreceiving screws 12 therethrough. Additionally, any of panels 54 mayinclude any of the screw blocking mechanisms or windows 62 noted above.Additionally, panels 54 may have one or more features configured toassist instruments to define trajectories of screws 12 through panel 54into vertebrae 4 as will be described in further detail below. Suchfeatures may include, for example, female bores 122, male protrusions,or the like.

In a first exemplary arrangement, as shown in FIG. 78A, similar to thearrangements of FIGS. 70-75 above, panel 54 may define one or moreapertures 16 for receiving screws 12 (not shown) therethrough. As shown,panel 54 may be configured to receive four screws 12 therethrough.Indeed, first and second screws 12 may be configured to extend throughpanel 54 into a first vertebra 4A, while third and fourth screws 12 maybe configured to extend through plate 54 into a second vertebra 4B. In afurther arrangement, as shown in FIG. 78B, panel 54 may define one ormore apertures 16 configured to receive six screws 12 (not shown)therethrough. Indeed, first and second screws 12 may be configured toextend through panel 54 into a first vertebra 4A, third and fourthscrews 12 may be configured to extend through plate 54 into a secondvertebra 4B, and fifth and sixth screws 12 may be configured to extendthrough plate 54 into a third vertebra 4C. Still further, as shown inFIG. 78C, panel 54 may define one or more apertures 16 configured toreceive eight screws 12 (not shown) therethrough. That is, first andsecond screws 12 may be configured to extend through panel 54 into afirst vertebra 4A, third and fourth screws 12 may be configured toextend through plate 54 into a second vertebra 4B, fifth and sixthscrews 12 may be configured to extend through plate 54 into a thirdvertebra 4C, and seventh and eighth screws 12 may be configured toextend through plate 54 into a fourth vertebra 4D. Alternatively, asshown in FIG. 78D, panel 54 may define one or more apertures 16configured to receive ten screws 12 (not shown) therethrough. Indeed,first and second screws 12 may be configured to extend through panel 54into a first vertebra 4A, third and fourth screws 12 may be configuredto extend through plate 54 into a second vertebra 4B, fifth and sixthscrews 12 may be configured to extend through plate 54 into a thirdvertebra 4C, seventh and eighth screws 12 may be configured to extendthrough plate 54 into a fourth vertebra 4D, and ninth and tenth screws12 may be configured to extend through plate 54 into a fifth vertebra4E. Still further, as shown in FIG. 78E, panel 54 may define one or moreapertures 16 configured to receive twelve screws 12 (not shown)therethrough. That is, first and second screws 12 may be configured toextend through panel 54 into a first vertebra 4A, third and fourthscrews 12 may be configured to extend through plate 54 into a secondvertebra 4B, fifth and sixth screws 12 may be configured to extendthrough plate 54 into a third vertebra 4C, seventh and eighth screws 12may be configured to extend through plate 54 into a fourth vertebra 4D,ninth and tenth screws 12 may be configured to extend through plate 54into a fifth vertebra 4E, and eleventh and twelfth screws 12 may beconfigured to extend through plate 54 into a sixth vertebra 4F.

It is to be understood that any of the previously disclosed features ofinterbody device 10 may be used together or separately. For example, anyof the disclosed screw blocking mechanisms noted above may be combinedwith any of the disclosed composite and/or standalone interbody devices10. Moreover, any of the interbody devices 10 disclosed herein mayinclude any one or more of coronal and/or sagittal plane windows 62.Additionally, any of the interbody devices 10 disclosed herein mayinclude any of packed bone graft material 70, retention members 72,graft containment sheath 120, anti-migration and/or anchoring features,anti-rotation features 90, insertion tool features 110, reduced profilekeel 94 features, and the like. Additionally, it is understood that anyinterbody device 10 disclosed herein may be appropriately sizeddepending on a desired therapeutic effect. For example, in somearrangements, interbody device 10 may have a width between about 10 mmand about 45 mm. For example, a width of an exemplary interbody device10 may be between about 10 mm and about 25 mm; between about 25 mm andabout 45 mm; or between about 15 mm and about 25 mm. Further, interbodydevice 10 may have a depth between about 10 mm and about 70 mm. Forexample, a depth of an exemplary interbody device 10 may be betweenabout 10 mm and about 20 mm; between about 20 mm and about 35 mm; orbetween about 30 mm and about 70 mm. Moreover, a height of an exemplaryinterbody device 10 may be between about 5 mm and about 25 mm. Further,a sagittal angle of lordosis may be between about 0° and about 15°; orbetween about 0° and about 12°.

Distractor and/or Trial Structure and Features

During a procedure for any of ACIF, ALIF, DLIF, PLIF, and/or TLIF, oneor more distractors and/or trials of various sizes may be utilized. Eachtrial and/or distractor may be forcibly inserted between adjacentvertebrae 4 so as to determine an appropriate size and/or positioning ofan interbody device 10 to be received within spinal column 2. To reducethe amount of insertion force required, an exemplary distractor and ortrial tool 150 may include one or more friction reducing elements suchas, for example, bearings, wheels, discs, rollers, and/or combinationsthereof. Indeed, as shown in FIG. 79, rollers 152 may be generallycylindrical. Alternatively, rollers 152 may include any appropriategeometric shape. In some arrangements, one or more rollers 152 may betextured or otherwise include protrusions or tread (not shown). As such,rollers 152 may score vertebrae 4 during insertion to promote bleedingtherefrom.

As shown in FIG. 79, an exemplary tool 150 may include a shaft 154coupled to a body 156 for manipulation thereof. That is, shaft 154 maybe any appropriate structure coupled to body 156 and having sufficientcolumnar strength to facilitate insertion and retraction of body 156between two adjacent vertebrae 4. In some arrangements, shaft 154 may beremovably coupled to body 156. As shown, body 156 may include a reducedprofile leading edge portion. For example, body 156 may include atapered nose 158. Nose 158 may assist a medical professional insert andretract body 156 between adjacent vertebrae 4. Body 156 and/or shaft 154may include any one or more of metal, plastic, and elastomer.Additionally, in some arrangements, body 156 may be configured forselective expansion. For example, body 156 may include upper and lowerbody portions (not shown) coupled together via any appropriate mechanism(not shown). An expandable member, such as, for example, a selectivelyinflatable balloon (not shown) may be positioned between the upper andlower body portions such that, upon inflation, body 156 expands inheight.

Body 156 may include one or more rollers 152. For example, body 156 mayinclude ten rollers 152, four along a top portion of body 156 configuredto reduce friction between body 156 and a first vertebra 4, and fouralong a bottom portion of body 156 configured to reduce friction betweenbody 156 and a second vertebra 4. Additionally, one or more rollers 152may be positioned along a top portion of nose 158 and a bottom portionof nose 158. Such an arrangement is merely exemplary. Rather, more orfewer rollers 152 may be positioned along body 156 and/or nose 158.Further, in some arrangements, a different number of rollers 152 may bepositioned along the top portion of body 156 and/or top portion of nose158 than the bottom portion of body 156 and/or the bottom portion ofnose 158. Further, rollers 152 may be individually rotatable orpivotable about individual axes 160. Accordingly, each roller 152 may berotated independently of remaining rollers 152. Alternatively, one ormore rollers 152 may be coupled together for simultaneous rotation. Forexample, a belt or similar structure (not shown) may extend across oneor more rollers 152 and/or axes 160 such that, rotation of one roller152 may result in the simultaneous rotation of at least one other roller152. For example, body 156 may include a continuous belt configured torotate about two or more wheel (e.g., rollers 152).

FIGS. 80A and 80B illustrate insertion of an exemplary tool 150. Forexample, as shown in FIG. 80A, prior to insertion of tool 150therebetween, a pair of adjacent vertebrae 4 may be spaced from oneanother by a height H₁. That is, an end plate of a first vertebra 4facing a second vertebra 4 may be positioned at a height of H₁ apartfrom a corresponding end plate of the second vertebra 4. In order todetermine an appropriate size and/or positioning of an interbody device10 to be received between adjacent vertebrae 4, tool 150 may be moved inthe direction of arrow A. Upon insertion of tool 150 in the direction A,first and second vertebra 4 may be distracted (e.g., spread apart) fromone another as shown in FIG. 80B. That is a first vertebra 4 may beurged away from the second vertebra 4 in the direction of arrow B, whilea second vertebra 4 may be urged away from the first vertebra 4 in thedirection of arrow C. Accordingly, after insertion of tool 150 between apair of adjacent vertebra 4, the pair of adjacent vertebrae 4 may bespaced from one another by a height H₂. That is, an end plate a firstvertebra 4 facing a second vertebra 4 may be positioned at a height ofH₂ apart from an end plate of the second vertebra 4 facing the firstvertebra 4. Further, upon insertion of tool 150, surrounding tensionbands (e.g., ligaments and/or muscles) may be loosened. Accordingly,following removal of tool 150 from the adjacent vertebrae 4 may collapsetowards one another, however, subsequent insertion of an interbodydevice 10 therebetween may require less force.

Further, as noted above, shaft 154 may be removably coupled to body 156.For example, shaft 154 may be threaded so as to cooperate with athreaded hole in body 156, or vice versa. In some arrangements, shaft154 may form a portion of a kit including shaft 154 and a plurality ofbodies 156. Each body 156 of the plurality of bodies 156 may have variednumber and/or configuration of rollers 152, nose 158 angle, and/orvaries dimensions (e.g., length, width, height, etc.). Accordingly, amedical professional may selectively choose one or more bodies 156 ofthe plurality of bodies 156 to couple to shaft 154. It is understoodthat any appropriate coupling structure other than threading is alsocontemplated. For example, any corresponding mating arrangement may beused to selectively couple and decouple shaft 154 from body 156.

In some arrangements, the above-noted features of body 156 may beincorporated into any of the above-noted interbody devices 10. Forexample, as discussed above, standalone and/or composite interbodydevices 10 may include a cage. Indeed, such a cage may include any ofthe arrangements illustrated in FIGS. 23-32. As shown in FIG. 81, aninterbody device 10 may include cage 170. Cage 170 may be similar tobody 156 as described above in connection with FIGS. 79, 80A, and 80B.For example, cage 170 may include one or more friction reducing elementssuch as, for example, bearings, wheels, discs, rollers 152, and/orcombinations thereof. Indeed, as shown in FIG. 81, rollers 152 may begenerally cylindrical. Alternatively, rollers 152 may include anyappropriate geometric shape. In some arrangements, one or more rollers152 may be textured. As such, rollers 152 may score vertebra 4 topromote bleeding therefrom.

As shown in FIG. 81, cage 170 may include four rollers 152. For example,one roller 152 along a top portion of cage 170 configured to reducefriction between interbody device 10 and a first vertebra 4, and oneroller 152 along a bottom portion of cage 170 configured to reducefriction between interbody device 10 and a second vertebra 4.Additionally, one or more rollers 152 may be positioned along a topportion of a nose 178 and a bottom portion of nose 178. Such anarrangement is merely exemplary. Rather, more or fewer rollers 152 maybe positioned along cage 170. Further, in some arrangements, a differentnumber of rollers 152 may be positioned along the top portion of cage170 and/or top portion of nose 178 than the bottom portion of cage 170and/or the bottom portion of nose 178. Rollers 152 of FIG. 81 may havesimilar features as those described above in connection with FIG. 79. Asshown in FIG. 81 the rollers 152 may be disposed relatively closer to adistal end of cage 170. Additionally, one or more of rollers 152 may bevertically slidable (e.g., radially inwardly and outwardly) as well asrotatable. For example, cage 170 may include one or more slots 168.Slots 168 may be configured (e.g., sized and positioned) so as toreceive axes 160 of rollers 152 therein. That is, a first side of eachaxis 160 may be received within a first slot 168 while a second side ofeach axis 160 may be received within a second, corresponding slot 168.In such a manner, each axis 160, and therefore, each roller 152, may beurged along slots 168 radially inwardly and outwardly relative to acentral axis of cage 170. Further, each axis 160 of each roller 152 maybe biased (e.g., spring biased) radially inwardly. Shaft 154 may beremovably coupled to cage 170 so as to urge each roller 152 radiallyoutwardly, as will be described in further detail below.

For example, FIGS. 82A-C illustrate insertion of an interbody devicecomprising a cage 170. Indeed, as shown in FIGS. 82A and 82B, shaft 154may inserted into cage 170 thereby urging rollers 152 radially outward.As such, rollers 152 may reduce friction between cage 170 and adjacentvertebrae 4 as cage 170 is moved in the direction of arrow A. Uponinsertion of cage 170 in the direction A, first and second vertebrae 4may be spread apart from one another as shown. That is, a first vertebra4 may be urged away from the second vertebra 4 in a direction of arrowB, while a second vertebra 4 may be urged away from the first vertebra 4in a direction of arrow C. After insertion of cage 170 between a pair ofadjacent vertebrae 4, shaft 154 may be removed, as shown in FIG. 82C.Accordingly, rollers 152 may no longer be urged radially outwardly.Further, due to the biasing of rollers 152, once shaft 154 is removedfrom cage 170, axes 160 of one or more rollers 152 may move along slots168 such that rollers 152 may retract into an interior of cage 170. Insome arrangements, shaft 154 may be hollow and include one or moreholes, through passages, or channels (not shown). In such cases, bonegraft or other suitable ingrowth promoting material may be injectedthrough shaft 154 into cage 170. In other words, shaft 154 may beconfigured for the delivery of bone graft therethrough and into cage170.

During insertion, one or more tools may be utilized to preparevertebra(e) 4 for insertion of interbody device 10. For example, asshown in FIG. 83, any appropriate tool may utilized to form one or moreholes or counter bores within vertebra 4 for receipt of suitablefasteners such as, for example, screws 12. Accordingly, as shown inFIGS. 83 and 86, following the removal of a tool(s), each vertebra 4 mayinclude one or more pilot holes 190 formed by a pilot hole feature (notshown) of a tool, and one or more counter bores 192 formed by reamer(not shown) of a tool. As shown in FIGS. 83 and 86, for example, twopilot holes 190 and two counterbores 192 may be formed in each vertebra4. Accordingly, the pair of adjacent vertebrae 4 may be prepared toreceive interbody device 10 therebetween. For example, as shown in FIGS.83 and 86, after formation of pilot holes 190 and/or counterbores 192,interbody device 10 may be inserted between adjacent vertebra 4.Interbody device 10 may include any of the previously describedfeatures, such as any of the above-noted screw blocking mechanisms.Further, as shown in FIGS. 83 and 84, interbody device 10 may compriseany of the above-noted standalone devices including a frame 60.Alternatively, as shown in FIGS. 86 and 87, interbody device 10 maycomprise any of the above-noted composite devices including a panel 54and cage portion 58. Following insertion between adjacent vertebrae 4,one or more screws 12 may be inserted through one or more apertures 16into a counterbore 192 and pilot hole 190 so as to secure interbodydevice 10 in place as shown in FIG. 85. For example, a first screw 12may be passed through a fist aperture 16, into a first counter bores 192and into a first pilot hole 190.

As noted above in connection with FIGS. 78A-78E, interbody devices 10may span more than two adjacent vertebra 4. For example, as shown inFIGS. 88 and 89, an exemplary interbody device 10 may be configured tocouple three or more vertebrae 4. For example, interbody device 10 maycomprise a composite device, including a panel 54 and cage portion 58.Panels 54 may be similar to those described above, and may include anyappropriate number of apertures 16 for receiving corresponding screws 12therethrough. Additionally, any of panels 54 may include any of thescrew blocking mechanisms or windows 62 noted above. For example, asshown in each of FIGS. 88 and 89, panel 54 may include six apertures 16,each configured to receive a screw therethrough and each associated withan exemplary offsetting element 24. Indeed, as shown in FIG. 88, panel54 may have a general H-shape, defining six apertures 16 along twocolumns and three rows. Accordingly, panel 54 may define three apertures16 on the left of a central longitudinal axis and three apertures 16 onthe right of the central longitudinal axis. Additionally, panel 54 maybe configured such that two apertures 16 are positioned along eachvertebra 4. As shown in FIG. 89, however, panel 54 may have a generalX-shape, defining six apertures 16. In such an arrangement, a centraltwo apertures 16 may be aligned along a central longitudinal axis, whiletwo apertures 16 are positioned to the left of the central longitudinalaxis and two apertures are positioned to the right of the centrallongitudinal axis. Additionally, panel 54 may be configured such thattwo apertures 16 are positioned along each vertebra 4. As shown in FIG.90, prior to placement of panel 54 and or cage portion 58 within spinalcolumn, one or more counterbores 192 and pilot holes 190 may be formed.Additionally, one or more grooves, recesses and/or channels 194 may beformed along an anterior surface of vertebra 4. Channel 194 may be sizedso as to receive at least a portion of frame 54 therein. Accordingly, asshown in FIG. 91, interbody device 10 may be received along spinalcolumn 2.

While principles of the present disclosure are described herein withreference to illustrative embodiments for particular applications, itshould be understood that the disclosure is not limited thereto. Thosehaving ordinary skill in the art and access to the teachings providedherein will recognize additional modifications, applications,embodiments, and substitution of equivalents all fall within the scopeof the embodiments described herein. Accordingly, the invention is notto be considered as limited by the foregoing description.

1. An intervertebral device, comprising: a body configured for insertionbetween adjacent vertebrae of a patient, the body including a wallhaving a first surface, a second surface, and a thickness extendingbetween the first and second surfaces, wherein the wall includes athrough aperture extending between a first opening on the first surfaceand a second opening on the second surface, the through apertureconfigured to receive a fastening element; a recess disposed in a sidewall of the aperture and extending into the thickness of the body in adirection substantially transverse to an axis of the aperture; and atleast one offsetting element positioned adjacent the through aperture,wherein the at least one offsetting element is configured to apply aforce to the fastening element.
 2. The device of claim 1, whereinapplication of a force on the fastening element by the at least oneoffsetting element is configured to laterally urge the fastening elementrelative to the recess.